Some more research, some more information. It seems that "headinclude" is not being included correctly into the pages. If I copy / paste the contents of "headinclude" directly in place of the include location (ie: in "FORUMHOME") then the page displays correctly.
It's only when the below is called from any page template other than CMS pages (ie: "DOWNLOADS2"):
Code:
{vb:raw headinclude}